The Synthesis and Properties of Dyers and Pigments Containing a 9,9′-Spirobifluorene Residue

The synthesis and properties of several azo and anthraquinonoid dyes containing a 9,9′-spirobifluorene residue are described. The azo dyes were prepared by diazotization of 2,2′ -diamino-9,9′-spirobifluorene and coupling to various commonly used coupling components. The anthraquinonoid dyes were made by condensation of the appropriate aminoanthraquinones with 9,9′-spirobifluorene-2,2′-dicarboxylic acid dichloride. The fastness to light of the so prepared has been compared with that of their non-spiro analogues. Also contains correspondence from C H Giles (JSDC, January 79, p. 25)